Four years ago, President Obama delivered an inaugural speech that many viewed as somber. He took office facing two wars and a global economic crisis.

INSKEEP: Yesterday, the president declared a decade of war is now ending. And he took a position in the economic battles that remain.

GREENE: He defended the role of government. And in a time of fierce partisanship, he told his supporters that he would need more than their votes - also their voices.

INSKEEP: We're hearing parts of the speech and responses to it throughout today's program. Here's NPR's Mara Liasson.

MARA LIASSON, BYLINE: Yesterday's inaugural ceremonies were smaller and a little more subdued than President Obama's first historic, euphoric celebration four years ago. Instead of 10 balls, there were just two last night, with performances from Katie Perry, Smokie Robinson, Stevie Wonder and Alicia Keys.

(SOUNDBITE OF SONG)

LIASSON: Earlier in the day, in the cold sunshine on the west front of the Capitol building, Mr. Obama took the oath of office.

PRESIDENT BARACK OBAMA: I, Barack Hussein Obama, do solemnly swear...

CHIEF JUSTICE JOHN ROBERTS: That I will faithfully execute...

OBAMA: ...that I will faithfully execute...

ROBERTS: .the office of president of the United States...

OBAMA: ...the office of president of the United States...

ROBERTS: ...and will, to the best of my ability...

OBAMA: ...and will, to the best of my ability...

ROBERTS: ...preserve, protect and defend...

OBAMA: ...preserve, protect and defend...

ROBERTS: ...the Constitution of the United States.

OBAMA: ...the Constitution of the United States.

ROBERTS: So help you God.

OBAMA: So help me God.

ROBERTS: Congratulations, Mr. President.

(APPLAUSE)

LIASSON: The coincidence of the King holiday, in the year that marks the 150th anniversary of emancipation, made civil rights a theme through the day's events.

The president took the oath on King's Bible and the invocation was given by Myrlie Evers, the widow of slain civil rights leader Medgar Evers.

MYRLIE EVERS: We come at this time to ask blessings upon our leaders, the president, vice president, members of Congress, all elected and appointed officials of the United States of America.

LIASSON: President Obama's inaugural address was short - just 18 minutes - and it was a ringing endorsement of the belief that government can help reduce economic and social inequality and make sure that America's prosperity rests, as he put it, on the broad shoulders of a rising middle class.

The president gave only a nod to reducing the deficit, saying we must make the hard choices to reduce the cost of health care. But he made a ringing defense of entitlement programs, saying that any one of us at any time may face a sudden illness.

OBAMA: The commitments we make to each other through Medicare and Medicaid and Social Security, these things do not sap our initiative, they strengthen us.

They do not make us a nation of takers; they free us to take the risks that make this country great.

LIASSON: That was a jab at Mitt Romney, who last year said the president bought off half the electorate with government goodies.

Unlike his first inaugural address, where the president talked in lofty terms about transcending partisanship, this speech was more openly liberal. He invoked Selma, Seneca Falls, but also Stonewall, a historic first.

OBAMA: Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law, for if we are truly created equal, then surely the love we commit to one another must be equal as well.

LIASSON: The speech was a preview of the more programmatic State of the Union address Mr. Obama will deliver three weeks from today. He grounded his agenda in American values. We will respond to the threat of climate change, he said, because failure to do so would betray future generations. And he cast immigration reform as a way to live up to America's founding principles.

OBAMA: Our journey is not complete until we find a better way to welcome the striving, hopeful immigrants who still see America as a land of opportunity, until bright young students and engineers are enlisted in our workforce rather than expelled from our country.

LIASSON: Mr. Obama expressed a sense of urgency - a desire to get done what he could in the small amount of time he has left to do it.

OBAMA: Progress does not compel us to settle centuries-long debates about the role of government for all time, but it does require us to act in our time.

LIASSON: We can't afford delay, he said, and he cautioned his supporters that, quote, "our work will be imperfect, our victories only partial." And he asked the public to stay engaged, particularly those supporters who propelled him to victory in the fall.

It was a festive non-partisan day, when politics took a backseat. There was a bipartisan lunch at the Capitol and a parade down Pennsylvania Avenue, and a memorable rendition of the national anthem by someone who's almost as big a celebrity as President Obama, Beyonce Knowles.